Source : Webster's Revised Unabridged Dictionary (1913)

Descending \De*scend"ing\, a.
   Of or pertaining to descent; moving downwards.

   {Descending constellations} or {signs} (Astron.), those
      through which the planets descent toward the south.

   {Descending node} (Astron.), that point in a planet's orbit
      where it intersects the ecliptic in passing southward.

   {Descending series} (Math.), a series in which each term is
      numerically smaller than the preceding one; also, a series
      arranged according to descending powers of a quantity.